Kennametal 1026730 Retention Knob BT40 5/8-11 Thread

Product Description

The KENNAMETAL 1026730 is a BT40 retention knob designed to secure tool holders in BT40 spindle tapers on CNC machining centers. It threads into the drawbar mechanism at 5/8-11 thread pitch, pulling the tool holder firmly into the spindle taper during operation. The knob features a 45-degree angle radius at the head, a knob diameter of 0.588 inches, and an overall length of 2.125 inches. With a neck diameter of 0.392 inches and a knob-to-flange length of 1.266 inches, this component meets the dimensional requirements for proper drawbar engagement and tool holder retention in BT40 tooling systems. It is a direct OEM-style replacement part suited for machine tool maintenance and tooling changeovers.

This retention knob is used in CNC vertical and horizontal machining centers equipped with BT40 spindle interfaces. It is typically installed during tool holder assembly or replaced as part of routine spindle maintenance when wear or damage to the existing knob is detected. Machinists, machine tool technicians, and toolroom personnel install this component. No through-coolant feature is present on this knob, making it appropriate for dry or flood-coolant setups where coolant delivery is handled externally rather than through the spindle center.

Key Features

• BT40 taper size for compatibility with standard BT40 spindle interfaces
• 5/8-11 thread size for engagement with BT40 drawbar mechanisms
• 45-degree angle radius head geometry for positive drawbar contact
• Knob diameter of 0.588 inches and neck diameter of 0.392 inches for precise dimensional fit
• Overall length of 2.125 inches with a knob-to-flange length of 1.266 inches
• Sold individually — package quantity of 1

Compatibility

Designed as an OEM-style replacement retention knob for CNC machining centers with BT40 spindle taper configurations.

Installation Notes

Installation should be performed by a qualified machinist or machine tool technician. Power down and lock out the machining center before removing or installing any spindle tooling components. Use the appropriate spanner wrench or retention knob installation tool to achieve proper torque — do not use impact tools, as overtightening can damage the drawbar or tool holder taper. Inspect the spindle taper and drawbar for wear before installing a replacement knob.